FBI Lab Analyzes DNA in Nancy Guthrie Disappearance Case at 100-Day Mark

One hundred days without answers has tested the family of missing Nancy Guthrie and the investigators on the case.

The probe into Guthrie's February 1 disappearance now hinges on DNA under analysis at the FBI laboratory in Quantico, Virginia. Detectives hope the sample identifies her abductor.

Guthrie, mother of Today show co-anchor Savannah Guthrie, vanished from her Tucson, Arizona, home. Pima County sheriff's detectives first sent DNA recovered there to a private lab in Florida. Weeks later, they forwarded it to the FBI's crime lab in Quantico, where sources say work continues.

Investigators have not disclosed details on the sample or its location.

"An item containing DNA such as a strand of hair found somewhere in a house is one thing, but a strand of hair near the victim's last known location, such as in her bed, would be a high priority for the FBI," said Lance Leising, a former FBI supervisory special agent in Arizona.

The DNA process, which includes family tree construction, forensic comparisons and elimination, takes far longer than on television crime shows, said retired FBI Supervisory Special Agent Jason Pack. "That kind of work is slow because it has to be right."

Pima County Sheriff Chris Nanos declined Monday to say if the DNA came from hair, bodily fluid or elsewhere. "It would be highly inappropriate of me to speak to the evidence. We have to keep the integrity of this case. If we make an arrest, that individual has the right to a fair trial, so I can't sit here and address all of that," he told CBS News. "We are working hard with all of our partners to resolve this case, and we will."

Bodily fluid would give the FBI a full DNA profile more easily than skin cells. A hair with its root or follicle offers better quality DNA than a shed strand.

Sources say lab techniques can enhance low-level samples, though the process drags on.

An earlier DNA sample from gloves found 2 miles from Guthrie's house traced back to a restaurant worker with no link to the case.

A Pima County Sheriff's Department statement Monday noted that scientific evidence processing and digital media analysis continue at the 100-day mark. Investigators pursue leads and tips, and urge tips from the public.

Ring doorbell camera video captured a ski-masked man in gloves and backpack at Guthrie's door the night she vanished. The FBI recovered it from backend residual data. Director Kash Patel said he spoke to Google leadership to obtain it.

Released publicly February 10, the video drew tips and searches that led nowhere. The FBI has released no further video but asks for tips via its line.

The FBI and sheriff's department have fielded thousands of tips. They sift phone data, surveillance video, GPS, app records, cloud data and social media.

"Sometimes the biggest breakthroughs come not from dramatic confessions or Hollywood-style moments, but from patient analysis and one tiny inconsistency that finally breaks a case open," Pack said.

Agents know the public sees silence as inaction. "That is not how major investigations work. The cameras may move on. The investigators usually do not," Pack said. "A hundred days feels like forever to a family. In investigative terms, it can still be early."

The lead detective and agents have re-interviewed witnesses, reviewed old tips and chased new ones. "They're looking for the one detail that did not fit the first time around," Pack said.

On Mother's Day, Savannah Guthrie posted on social media: "We will never stop looking for you. We will never be at peace until we find you."

The FBI offers $50,000 for information leading to Guthrie's recovery or the arrest and conviction of those involved. Her family adds $1 million. Local Crime Stoppers offers $2,500 plus $100,000 from Milwaukee attorney Michael Hupy.

"Someone knows something that can make the difference," Guthrie wrote. "Please keep praying. Bring her home."